After being manufactured and filled, packs are provided with a variety of labels, revenue stamps, coupons or the like, which are attached to the outer side of the pack, e.g. by adhesive bonding. It is crucial that the blank is attached in a correct position. This is particularly important for cigarette packs which are provided with a revenue stamp or closure strip. A skewed position is undesirable.
The inspection of blanks by means of the laser triangulation method is known as disclosed, for instance, by DE 199 04 671 A1. However, this requires the use of complex and costly laser triangulation measuring systems.